Process of tempering corrugated walls.



W. M. FULTON. PROCESS OF TEMPEBING CORRUGATED WALLS. APPLICATlOh FILED NOV. 20. l9l6.

1 ,293,078, Patented Feb. 4, 1919.

STATES PATENT OFFICE.

WESTON M. 'FULTON, OF .KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON COMPANY, OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAIN'E.

PROCESS OF TEMPERING CORRUGATED WALLS.

' To all whom it may concern:

Be it known that I, WESTON M. FULTON, a citizen of the United States of America, and a resident of Knoxville, Tennessee, have invented a new and useful Improvement in Processes. of Tempering Corrugated Walls, which invention is fully set forth in the following specification.

This invention relates to a process of hardening and tempering a corrugated wall, and is particularly adapted to the production of such walls for use in collapsible and expansible vessels designed to confine fluids under pressure. 1

It has for an object the production of corrugated walls of high resilience, of great strength and durability, and which can be collapsed and expanded many times substantially without injury thereto.

Flexible corrugated walls of the type referred to are repeatedly subjected to ten- ,sional, compression and bending stresses. If

they be constructed of soft steel, these stresses soon produce crystallization and fracture at the curved portions of the corrugations, owing to frequent straining of the metal beyond its elastic limit. It is an object of this invention to so harden and temper the portions of the corrugations subjected to the greater stresses as to render these walls more durable and resistant to strains while securing a proper degree of resiliency therein.

- A further object of this invention is to provide a hardening and tempering process wherein diiferent portions of the wall have different degrees of hardness. Other ob- *jects will appear as the description of the invention proceeds.

Stated briefly, the invention comprises the process of hardening and tempering a corrugated wall which consists in heating said wall and subjecting the same to a cooling medium while said wall is difi'erentially protected from said medium, whereby different portions of said wall are brought to their final cooled condition at different rates, re-

sulting in diiferent degrees of hardness.

The inventive idea involved is capable of a variety of expressions, one of which, for the purpose of illustration, is hereinafter specifically described, but it is to be expressly understood that such illustration is not intended as a definition of the limits of the in- Specification of Letters Patent.

Patented Feb. 4, 1919.

Application filed November 20, 1916. Serial No. 132.461.

vention, reference being had to the appended claimsvfor that purpose.

On the accompanying drawings, appropriate apparatus is illustrated for the carrying out of the process, but it is to be understood that such apparatus has been selected for the purpose of illustration only and is in no respect definitive of the scope of the invention, as the invention idea is not de-- corrugated wall provided with heat-absorptive means in accordance with the present invention;

Fig. 2 is a-plan of one of the top and bottom clamping members;

Fig. 3 is a lan of a ring designed to be positioned wit in a space between adjacent corarugations opening exteriorly of the wall; an

Fig. 4 is a plan of a ring designed to be positioned within a space between adjacent corrugations openin lnteriorly of the wall.

In accordance wit the present invention, a metal blank, preferably of a good grade of steel, is corrugated in any?" suitable way while in its softest state, the same being annealed frequently to withdraw temper unavoidably formed therein by the working of the metal.

The corrugated wall is then provided with heat-absorptive means in contact with those portions of the wall which aresubject to less strain than other ortions thereof, such heat-absorptive means eing maintained out of contact with those portions which it is desired shall be harder or more highly temered. In the form shown (Fig. 1), metal locks 1 and 2, in the form of rings, are positioned between and in contact with the lateral or flat portions of a corrugated wall 3, said rings not contacting with the portions of said corrugations constituting the bends therein. Said rings are preferably of a thickness equal to the distance between adjacent lateral walls of the corrugations when said Wall is in its unstressed condition.

. are quickly chilled by the bath and thereby The rings fitting into the spaces between lateral portions of the corrugations which open exteriorly of the wall may desirably be made in two sections 4 and 5, as shown (Fig 3). The rings fitting into the spaces between lateral portions of the corrugations 18, whereby the cooling medium may have free access to the interior of the wall. 7

The corrugated wall, with its interposed rings of heat-absorptive material, is then heated until the same is brought to an appropriate temperature, preferably that corresponding to a dull-red heat. The wall and heat-absorptive means in contact therewith v are then immersed in a chilling bath, preferably of oil. The portions of the wall out of contact with the heat-absorptive rings given a high degree of hardness or te'mper. The lateral walls of the corrugations which are in contact with the heat-absorptive rings are protected from the chilling efiect of the bath and, owing to the gradual giving up of heat by the rings, such portions of the wall are hardened to a less extent or may be left substantially without temper. Furthermore, the delivery of heat by the interposed rings to the portions of the corrugations in contact therewith affects the adjacent portions of the corrugations which are out of contact with the heat-absorptive means, thereby.

drawing the temper therein but to different degrees in accordance with the distance from the portions in contact with the aforesaid rings. Thereby is there no abrupt change of temper or hardness between the lateral walls and the curved walls of the corrugations.

By the use of heat-absorptive. rings of a thickness equal to the space between adjacent lateral walls, and by the clamping of the corrugated wall between such heat-absorptive rings, the vessel is firmly supported during the. hardening or tempering process with a consequent prevention of the wall becoming distorted or warped in any way during the subsequent chilling of the same.

While the process hasbeen described as applied only to hardening and tempering of the bends of the corrugations, it will be apparent that, by the selection of appropriate materlal and rings ofappropriate' size and shape, more or less of the corrugated walls may be hardened and tempered and the range and gradation of temper may be suitably varied in accordance with the nature of the material used in the wall and with the uses to which such wall is to be put. The invention, therefore, is not to be restricted to hardening and tempering the bends only of the corrugations nor to the use of heat-absorptive means of the shape, size or kind illus trated on the drawings, the invention being directed broadly to difie'rentially protecting of the temper from the hardened portions and insures the aforesaid gradation of hardness.

What is claimed is: a 1. The process of difierentially hardening and tempering a corrugatedwall which comcontact with the lateral walls of the corrugations but out of contact with the bends thereof, heating said corrugated wall and heat-absorptive means, and subjecting the whole to a cooling medium.

2. The process of difi'erentially hardening prises maintaining heat-absorptive means in and tempering a corrugated wall which comprises interposing metal blocks between and in contact with the lateral walls of the corrugations but out of contact with the bends thereof, heating said corrugated wall and blocks, and subjecting the whole to a cooling medium.

3. The process of differentially hardening and tempering a corrugated wall which comprises maintaining heat-absorptive means in contact with portions of the walls of the corrugations but out of contact with other portions thereof, heating said corrugated wall and heat-absorptive means, and subjecting the same to a cooling medium.

4. The process of difierentially hardening and tempering a corrugated wall which comprises heating said wall, and subjecting the same to a cooling medium while retarding the cooling of portions of said wall and producing'a gradation of hardness in other portions of said wall.

5. The process of differentially hardenin and tempering a corrugated wall whic comprises heating said wall with heat-absorptive means in contact with the lateral portions thereof, and subjecting the whole to a cooling medium.

6. The process of differentially hardenin and tempering a corrugated wall whic in contact with the lateral portions of said wall to prevent the rapid chilling of such portions.

7. The process of difierentially hardening and tempering a corrugated wall which comprises heating said wall, and subjecting the same to a cooling mediumwith heated means in contact with portions ofsaid wall to tlllraw the temper in other portions of said wa o 8. The process of diflferentially hardening and tempering a corrugated wall which comprises heating said wall, and subjecting the same to a cooling medium with heated meats in contact with portions of said wall to control the cooling of the same and to give up heatto other portions of said wall.

9. The process of making a corrugated steel wall which comprises corrugating a blank of soft steel, and differentially hardening and tempering the same by heating said wall and subjecting the same to a cooling medium while retarding the cooling of portions of said wall and producing a gradatioili1 of hardness in other portions of said Wa 10. The process of making a corrugated steel wall which comprises corrugating a blank of soft steel, and differentially hardening and tempering the same by heating said wall with heat-absorptive means in contact with the lateral portions thereof and subjecting the whole to a cooling medium.

11; The process of making a corrugated steel wall which comprises corrugating a blank' of soft steel, maintaining heat-absorptive means in contact with portions of the walls of the corrugations but outof contact with other portions thereof, heating said corrugated wall and heat-absorptive means and subjecting the same to a cooling medium.

12. The process of making a corrugated steel wall which comprises corrugating a blank of soft steel, maintaining heat-absorptive means in contact with the lateral walls of the corrugations but out of contact with the bends thereof, heatingsaid corrugated wall and heat-absorptive means, and subjecting the whole to a cooling medium.

13. The process of making a corrugated steel wall which comprises corrugating. a-

blank of soft steel, interposing metal blocks between and in contact with the lateral walls of the corrugations but out of contact with the bends thereof, heating said corrugated wall and blocks, and sub ecting the whole ing medium with heated means in contact with portions of said wall to draw the temper in other portions of said wall;

16. The process of making a corrugated steel wall which comprises corrugating a blank of soft steel and differentially hardening and tempering the ,same by heating said wall and subjecting the same to a cooling medium with heated means in contact with portions of said wall to control the .cooling of the same and to give up heat to other portions of said'wall.

In testimony"whereof I- have slgned this specification.

wE s'roN M. FULTON. 

